


Nacre

by anactoria



Category: Supernatural
Genre: Ambiguous/Open Ending, Angelic Grace, Future Fic, Gen, Implied Lucifer/Sam Winchester, Lucifer Possessing Sam Winchester, M/M, Season/Series 11
Language: English
Status: Completed
Published: 2016-03-09
Updated: 2016-03-09
Packaged: 2018-05-25 14:48:07
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,793
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6199195
Author URL: https://archiveofourown.org/users/anactoria/pseuds/anactoria
Summary: <blockquote class="userstuff">
              <p>Two halves made whole, too late.</p>
            </blockquote>





	Nacre

**Author's Note:**

> Fair warning: while I'm mostly pretty positive about the Carver era, I'm not best impressed with either the Casifer storyline or any of Lucifer's characterisation post-S5. This is me attempting to fanwank that part of current canon into something that works for me, only I've no idea if it actually does work for me. Uh, read at your own risk, I guess?

“If I say yes,” Sam asks, blood dripping from the palm of his left hand, “will Cas make it?”

There’s a visceral wrongness about seeing Lucifer’s expressions on Cas’s face. Unconcerned quirk of the mouth, eyes widening with a mock-innocence so unlike Cas’s intensity that Sam can’t imagine how he ever failed to see the difference. All that don’t-care looseness. Watching it gives Sam this lurch inside that’s like spinning off the road, something twisting up deep in his guts.

He feels it differently than Dean does, he knows. For Dean, it’s all about seeing Cas be not-Cas, the revulsion of some other creature wearing his best friend like a cheap suit. And Sam gets that. Truly he does. But in that deep-down place, in ways he tries not to dwell on too hard or for too long, he’s pretty sure it isn’t about Cas at all.

Sam thought he understood this creature, once. 

There wasn’t any comfort in the thought, just the inevitable heaviness of looking in the mirror the morning after a bad decision and hating what you see. He’d be insane to miss the familiarity—and he doesn’t, when he thinks about it with the rational part of his brain. He _doesn’t_. It’s just that he still aches like he does.

Dean would freak if Sam ever told him as much. Only Dean isn’t here right now. Amara’s coming for them and Dean is at her side, blinded by her presence and deafened to everything Sam says. Dean is ready to offer up his soul on a silver platter, and Dean will never do that again, not on Sam’s watch.

Sam grits his teeth. “I won’t ask again,” he says, hand inching toward the banishing sigil on the wall. His bluff sounds as weak as it feels.

Lucifer shrugs at him with Cas’s shoulders, cracks a little smile. There’s a blister at the corner of Cas’s mouth, oozing blood. The skin on his face is peeling. Sam’s pretty sure angel mojo can’t heal this stuff. Cas is gonna have scars.

“Will he make it?” Lucifer draws out the sentence, pausing like a gameshow host about to announce the winner. “Probably.” 

Sam doesn’t lower his hand. “Probably isn’t good enough.” He can’t entertain the thought of Dean coming back to himself and finding both his brother and his best friend gone. He shouldn’t be hesitating—should’ve learned his lesson about putting their little family above all the crap raining down upon the world at large—but he can’t.

That gets him a teen-drama-worthy eyeroll. “He’ll be fine. Maybe a little singed.”

All Sam needed to hear, and it should be a relief, but it’s terrifying. He sucks in a breath, steps away from the sigil.

Lucifer’s expression wavers. For a moment, he’s very still, turned inward. There’s a struggle there as Sam watches—and then, then, it’s Cas looking back at him.

“Sam,” he says, ragged-voiced, huge heartbroken eyes. “No.”

Sam swallows. Presses his hand over the cut on his palm. 

“You have to look after Dean. You hear me, Cas? You gotta look after him.” He closes his eyes, then—before he can see Cas’s disappointment, before he can see it harden into something else. And he says, “Yes.”

There is light.

His eyes close, a useless reflex, a tremor running through him from head to toe. It’s blinding, all of it, the sense of something vast unfolding, the light seeping in beneath his eyelids. 

But it’s done now. There’s no running from it. Lucifer is a cold sun, all-consuming, and Sam’s gone and thrown himself into the heart of it. White heat; burning cold; terror too vast to be reasoned with. It’s like napalm in the lungs, thundering in his veins. He can’t breathe. The pressure’s too much, the _weight_ of it—

 

—something at the core of him cracks apart—

 

—and what floods out of it is memory.

 

First, the memory of falling. 

Down through depthless black. Down to the center of the earth and further still. Impossible distances. The winds of that between-place howling by him, and Dean’s voice echoing in his ears.

 _I’m not gonna leave you_ , it says. Sam squeezes his eyes shut and sees daylight glinting off their initials carved into the Impala’s paneling. Toy soldier. Shards of broken windscreen. He tries to hold on to the rush of memories; the strength they gave him. A solid thing to cling to as the world whips past.

There’s something else, too. A bitter grief that isn’t his own—too vast and too alien for that—but that has its human echo in his memories, an abandoned convent and a voicemail message. 

_You’re a monster_. Dean’s voice. Michael’s voice.

_I’m not gonna leave you._

Only one of those things turned out to be a lie. He finds that he hurts for the one that didn’t.

Relief and terror and raw nerves and rage. Sam fights as he falls, but there’s no untangling it. What belongs to him and what doesn’t. What’s him and what is Lucifer. He can’t help but feel it, the breath ripped from his lungs.

There’s no impact when the fall ends. He doesn’t find himself spattered across stony ground and still conscious, like he feared. There’s just—stillness. It’s cold, too dark to see. His breath rasps in the silence. He tries to steady it, to gather himself, but finds he has no control of his limbs.

His moment is over, then. That was the last of his free will.

Waiting for the Devil’s anger, he feels his heartbeat in his throat. He’d flinch if he could. Remembers the snap of Bobby’s spine beneath his hand. Cas vanishing in a shower of blood.

The anger doesn’t come. Not yet. Instead, Lucifer raises Sam’s right hand, touches his fingertips to his lips. They tremble with emotion that isn’t his own, except that it kind of is. ( _You’re a monster. I’m not gonna leave you._ )

It feels like being kissed.

Somehow, that’s worse than whatever he was expecting. The sympathy-ache, the resonance of almost-shared memory. Understanding, despite everything; despite the fact that Dean’s blood is still on their knuckles.

_I’m sorry._

It’s the echo of his own voice inside his head. He didn’t mean to say it. He doesn’t think he meant to say it. 

_Not for this. But—_

The breath that passes his lips isn’t quite a laugh. “Maybe I should be the one saying that to you.”

Sam wants to stare. _Why? You didn’t have some epiphany on the way down here. You still think you were right._

Lucifer shakes his head. His voice is very gentle. “Not for anything I did on Earth. For what I’m about to do.”

Dread clenches in Sam’s stomach. _Which is?_

“Something very selfish.”

Sam waits for elaboration, but it doesn’t come. Not in words, anyway. Just the quiet agony of separation.

It’s nothing like when he kicked Gadreel out of his skull, that tearing rush of light. (The memory a future echo, a reminder that he isn’t really here, that this is the opposite of what’s happening right now.) Instead it’s careful, a deliberate untangling, threads of grace cut through with scalpel precision.

Another memory: Cas at his side in the bunker, explaining how no angel can possess a host without leaving part of itself behind. Sam understood the implications at the time; was careful to bury them under resentment and worry and the fight to save Dean. It never occurred to him that the angel might get to choose which part it left behind.

Another: thunder rumbling across the waste of Limbo. A different cage, a casual moue of amusement. _Prison life… hasn’t really agreed with Michael_. Not even a hint of sorrow.

The final thread breaks. Lucifer steps free of him, wearing the face Sam knows from his dreams, and he feels a brief, giddy spike of relief that it isn’t his own. 

His soul closes over that final piece of grace like water. 

The Devil’s grief. The Devil’s pain. The Devil’s envy, his _love_. Walled up in some recess of Sam’s being, so deep that neither Cas nor Death himself could sense it. It’s been there this whole time.

In the memory, Lucifer stands before him. Looks at him with cold, cold eyes and a smile that’s all teeth. “Well done, Sam,” he says, “you won,” and there is nothing gentle left of him now.

In the present, Sam feels it come loose. That piece of grace, of _Lucifer_ , so carefully folded away inside him, plucked out like a pearl from an oyster. He hadn’t even known it was there. 

It’s a little like after the Trials, he thinks. He got so used to pain and exhaustion he stopped noticing them, only realized he’d been hurting when he stopped. Now he feels a weight lifted from him and reunited with the rest of itself and he blinks, wide-eyed, like he’s surfacing. Lucifer doesn’t stop him.

Sam feels the shock of the reunion, too. The rush of love and grief that aren’t his own. For a moment, the Devil stares blindsided out of his eyes, frozen where he stands as the avalanche of lost things tumbles down on them.

Cas is staring at them, sprawled on his back on the floor. He looks like he’s in a bad way—he must’ve collapsed without Lucifer holding him up. Now, he pulls himself wincing to his feet. He squints at whatever he sees as he moves toward them, some kind of recognition dawning on his face.

“Sam?” he says, and of course Sam can’t reply. Cas frowns, and Sam sees him thinking, sees him gather himself, before he tries, tentative “…brother?”

Lucifer doesn’t laugh like Sam is expecting. He cocks Sam’s head, and says—quietly, like he’s trying it out—“Maybe.”

It feels like a question, but not one for Cas. Sam doesn’t have an answer. He might, if he only had time to think.

But the floor beneath them begins to shake. Plaster falls from the walls.

“Cas,” Sam thinks, as hard as he can, and then he’s surprised to find he’s spoken the word aloud. No time to wonder about it, though. “You have to get out of here. Find Dean!”

Cas stares at them a moment longer. Then he nods, and runs for the exit.

They stand very still as the walls crumble. The Devil’s sorrow beats in Sam’s chest.

If they had an hour, a moment, he’d wonder at it. He’d turn the memory over and over in his mind. He would figure out what to do with knowing this.

“Lucifer—” he starts to say, and Lucifer hushes him with a finger to his lips.

The ground cracks open. There is darkness.


End file.
